Atopy and Pulmonary Function Among Healthy-weight and Overweight/Obese Children with Asthma.

Introduction Epidemiologic studies have found low/absence of atopy in obese asthmatic children, but the association or lack thereof of atopy with disease morbidity, including pulmonary function, in obese asthma is not well understood. We sought to define the association of atopy with pulmonary function in overweight/obese minority children with asthma. Methods In a retrospective chart review of 200 predominantly minority children evaluated at an academic Pediatric Asthma Center over 5 years, we compared the prevalence of atopy, defined as ≥1 positive skin prick test or serum-specific IgE quantification to environmental allergens, and its association with pulmonary function in overweight/obese (body mass index (BMI) >85%) (n=99) to healthy-weight children (BMI 5-85% for age) (n=101). Results In a cohort comprised of 47.5% Hispanics and 39.5% African Americans, 81% of overweight/obese and 74% of healthy-weight children were atopic. While atopic healthy-weight children had lower percent-predicted FEV1 (93±13.6 vs. 107%±33.2, p =0.03) and lower percent-predicted FVC (93%± 12.2 vs 104%±16.1, p=0.01) as compared to non-atopic children, atopy was not associated with FEV1 (p=0.7) or FVC (p=0.17) in overweight/obese children. Adjusting for demographic and clinical variables, atopy was found to be an independent predictor of FEV1 and FVC in healthy-weight (β=-2.4, p=0.07 and β= -1.7, p=0.04, respectively) but not in overweight/obese children (β=0.6, p=0.5 and β= 0.8, p=0.3). Conclusions Atopy is associated with lower lung function in healthy-weight asthmatics but not in overweight/obese asthmatics, supporting the role of non-allergic mechanisms in disease burden in pediatric obesity-related asthma. This article is protected by copyright. All rights reserved.